What is Data Manipulation Language (DML)? Easy-to-understand explanation of basic concepts of database operations
Data Manipulation Language (DML) is a subset of SQL (Structured Query Language) that enables users to manipulate data within a database. It provides a set of commands that allow users to insert, update, delete, and retrieve data from database tables. DML is specifically designed to perform data operations rather than defining or modifying database structures.
Insert: The INSERT statement in DML is used to add new rows of data into a table. It allows users to specify the columns and their corresponding values that need to be inserted. For example, to add a new employee to the ‘employees’ table, you would use the INSERT statement to specify the employee’s name, age, and department.
Update: The UPDATE statement allows users to modify existing data within a table. It enables users to update one or more columns of one or more rows based on a specified condition. For instance, if you want to update the salary of an employee, you can use the UPDATE statement to set the new salary value based on the employee’s ID.
Delete: The DELETE statement is used to remove one or more rows from a table. It allows users to specify a condition to determine which rows should be deleted. For example, if you want to remove all inactive users from the ‘users’ table, you can use the DELETE statement with the condition that filters out inactive users.
Select: The SELECT statement is primarily used to retrieve data from a database table. It allows users to specify one or more tables and columns from which to retrieve data. Additionally, you can use the SELECT statement with conditions, joins, and aggregations to perform more complex data retrieval operations. For example, you can use the SELECT statement with a WHERE clause to retrieve all employees whose age is below 30.
DML statements are fundamental to performing day-to-day data operations in a database. They provide users with the ability to interact with data and modify its content based on their requirements. It is essential for anyone working with databases to have a good understanding of DML and its capabilities to effectively manage and manipulate data.
By mastering DML, database users can efficiently update, delete, and retrieve data, allowing them to effectively manage and maintain the integrity of their database systems. Whether you’re a data analyst, a software developer, or a database administrator, understanding the basic concepts and usage of DML is crucial for successful data management.